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oil pan bolt questions

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Wings

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oil pan bolt questions

Rebuilt my bj8 engine 500 or so miles ago (broke another crank, thats 2 now) I just changed the oil for the second time it was a bit wetter underneath than i expected, looks like the front timing cover again, gonna tighten the bolts as best i can to see if that helps
on the timing cover it was just the bottom 3 bolts that took a tighten

BUT.....ALL (24) of the (DW aluminum) oil pan bolts took a tighten about 1/2 to 3/4 turn each I did these when we assembled so i am aware of the pressure applied. these oil pan bolts are modern grade 8, 24 count thread(i think, fine thread anyway) 550 miles and working themselves out ????
thoughts here,, guys
hot oil shrinking the cork?
go back to originals incase bottom of block is wintworth?
thread lock?
do what i do to valve cover? apply sealent on both sides (of oil pan)


thoughts
 
Re: oil pan bolt questions

Rebuilt my bj8 engine 500 or so miles ago (broke another crank, thats 2 now.

I would suggest before you rebuild it again you have your block Line bored,--Fwiw--Keoke
 
Re: oil pan bolt questions

Keoke said:
Rebuilt my bj8 engine 500 or so miles ago (broke another crank, thats 2 now.

I would suggest before you rebuild it again you have your block Line bored,--Fwiw--Keoke
Click to expand...
That, and have your dampener checked or replaced.

As for the oil pan, as I'm sure you know, aluminum and cast iron expand at different rates when heated. The aluminum "grows" more, stretching the bolts. Once cool again, they appear to be loose.

I've never put an alloy pan on a Healey (nor would I, considering all the smashed steel pans I've seen in the past 3+ decades) but my recommendation would be to place a belleville-type washer under each bolt, to allow for the expansion/contraction. Might even consider a low-to medium strength Loctite for added peace of mind.

Ironically, my BMWs use alloy pans on cast iron blocks, but there is no problem with the bolts "loosening." BMW does however, use a pretty sophisticated steel/rubber composite gasket and a VERY LOW torque value (12 Nm).
 
Re: oil pan bolt questions

Just another thought, you may want to consider replacing the SAE bolts with BMC OEM type. I had an English friend stop by several weeks ago and was looking at my MG and Healey pieces and asked me what I did for engine sheetmetal hardware, I advised I tried to use AN bolts, he said but the thread pitch is slightly different. I didn't know this.

Also in the past few years there have been some inferior SAE /grade 8 hardware on the market from over seas. You may have several things stacking up against you: different (deffective?) pitch angle, and different expansion rates.

Barry
 
Re: oil pan bolt questions

BMC used 2 fine thread srandards - NSF and UNF, apart from odd uses of BA in electrical gear.

No way will a BSF bolt fit in a UNF thread, and vice versa. UNF is the same as, indeed is the semantically-correct term for, SAE.

Some of my fellow-countrymen aren't always right.
 
Re: oil pan bolt questions

i removed and took a close look at the grade 8 oil pan bolts i'm using. It seems like the thread going into the block are a slight different pitch (the brass color is stripped off).
turns out DW has a mounting kit i was not aware of that addresses this issue... ordered
i will use the belleville style(thanks randy)washer though. w/thread loc
thanks for all the input
 
Re: oil pan bolt questions

Speaking of bashed in oil pans, can one be beaten (roughly) back into shape or do you risk distorting the sealing surface?
 
Re: oil pan bolt questions

Thank you very much, Wings, for the contact info. Now all I have to do is get motivated to remove the pan and ship it off.
 
Re: oil pan bolt questions

Two broken cranks in a BJ8 motor? I think you need a new engine builder. I've been racing a 3000 for over 25 years, and I know a lot of other racers using 6 cylinder motors. We don't usually break 6 cylinder cranks. As for the damper and the harmonics - the harmonics come in around 5900 RPM. So tell us, what is it that you are doing to that poor motor to break cranks?
 
Re: oil pan bolt questions

Hi Richard
How the heck are you?
love your bearings
why broke my cranks.... because you ask
1st time over reving, racing with a 5 liter ponycar
2nd time(your bearings) found my normal clutch (xke 9.5) was slipping at about 120 mph
so i replaced it with a cooper faced DW paddle type clutch(want to buy a paddle clutch w/less than 400 miles on it?)
went into 2nd from 4th @ a round 90 mph with breaking but my foot on clutch /slowed down, dropped the clutch (no were near the 5900 harmonic distortion you told me about) the crank snapped.
I could have detuned my design
but just couldn't, i had a new billet crank made (I remembered you telling me about your rods), w/billet rods(-1lb less than oem each) and i am happy
crankshaft was balanced to 0 ati damper(your pulley design thank you very much) and clutch pp along w/rods and bearings are balanced on new crank to .3 gram (4 r&p are identical weight) the middle two are off from them by three tenths a gram( triple beam) nice drive train
I did this one myself instead of from a check book car was off the road for a year
will you be at sears point later this month
 
Re: oil pan bolt questions

Pitch is number threads per inch, but the Whitworth thread is a slightly different angle, radiused roots & crests and slightly different pitch diameter, that's probably why some material was removed from your fasteners.
 
Re: oil pan bolt questions

What's the bolt diameter? 5/16"? No way you'd get a 5/16"W bolt into a 5/16UNF thread, or vice-versa, without serious graunching, not just a bit of micron-thick plating. Is the thread in the block a coarse thread? Being in CI, I'd expect not.
 
Re: oil pan bolt questions

Nor will you get 1/4 BSF or 1/4 Whit to go into 1/4 NF without serious wrenching, thread-stripping and general mayhem. They just won't go.
 
Re: oil pan bolt questions

Speaking of oil pans. You can hammer and dolly an oil pan back to its original shape. Sometimes it takes a torch to heat up a really bad wrinkle to move it around a bit, but this stuff is not rocket science. I think many people are intimidated by a damaged pan, or by bent sheet metal anywhere. Working out the dents in the bottom of the pan will not effect the mounting flange at the top of the pan. My advise is to go for it. Buy a book. Buy a dolly. Buy a couple of hammers. If it cracks - weld it up. Or, spend $400 for an aluminum oil pan that you don't really need (and you do not need it to stiffen up your block as DW suggests). But, it's your money - and only my opinion. Cheers
 
Re: oil pan bolt questions

As Richard said it isn't rocket science and if you've really skilled you can make it look like this.

Dougie
 
Re: oil pan bolt questions

Dougie
Might i ask are there any modifications that need to be done to your dip stick with the dmd oil pan?
oil pan protected by the frame... no brainier
 
Re: oil pan bolt questions

No modifications to the dipstick needed. With a 2 qt. accusump oil accumulator and a 12 row oil cooler it takes about 10.5 qts. to fill to the "max" line.

Dougie
 
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